Polyisocyanates containing sulphonic acid or sulphonate groups

Abstract

Liquid and substantially non-crystalline aromatic polyisocyanate sulphonic acids or sulphonates and a process for the preparation thereof are disclosed which polyisocyanates are eminently suitable as presursors in the production of polyurethane foam resins and/or emulsifiers or wetting agents, hydraulic binders, thickening agents and cross-linking agents for vinyl polymers, polyurethanes, polyureas and polyamides.

What is claimed is: 
     
       1. Liquid aromatic polyisocyanates, which contain sulphonic acid or sulphonate groups, prepared by a process comprising reacting at a temperature of from about -20°C to about 200°C: A. a liquid multicomponent mixture of aromatic polyisocyanate having an NCO content of from about 18% to about 35% by weight, and a viscosity of from about 50 to about 10,000 cP at 25°C, said liquid multicomponent mixture selected from the group consisting of: i. phosgenation products of the condensates of (a) aniline or alkyl groups substituted anilines and (b) aldehydes or ketones;   ii. distillation residues obtained from the distillation of crude tolylene diisocyanate mixtures and which residues contain less than about 50% by weight of free tolylene diisocyanate isomers;   iii. a reaction product of (i) or (ii) and 0.2 to 25 mol percent of an organic polyol;   iv. a mixture of (i) with from 1 to 30% by weight of tolylene diisocyanate or 2,4'-diphenylmethane diisocyanate; and   v. mixtures thereof; and     B. from about 0.1 to about 10% by weight, based on the weight of said liquid multicomponent mixture of sulphur trioxide or an equivalent quantity of oleum, sulphuric acid, or chlorosulphonic acid.   
     
     
       2. The polyisocyanate of claim 1, wherein the sulphonating reaction is carried out in an inert solvent. 
     
     
       3. The polyisocyanate of claim 1, wherein the sulphonated reaction product is partially or completely neutralized with a basic compound. 
     
     
       4. The polyisocyanate of claim 1 wherein the liquid multicomponent mixture of aromatic polyisocyanates used is a phosgenation product of aniline/formaldehyde condensates which contains 20 to 80% by weight of dinuclear diisocyanates, 8 to 70% by weight of trinuclear triisocyanates, 1 to 20% by weight of tetranuclear tetraisocyanates and 1 to 40% by weight of higher nuclear polyisocyanates.